JHDM3_JMJD2: The JHDM3_JMJD2 group of proteins has orthologues from yeast to humans. In higher eukaryotes, proteins of this family contain JmjN, PHD and Tudor domains in addition to the JmjC domain. There are four JHDM3_JMJD2 genes (JHDM3A_JMJD2A, JMJD2B, JMJD2C and JMJD2D) in the human genome, each of which has orthologues in the mouse. JHDM3A_JMJD2A was originally identified as a transcriptional repressor associated with the NCoR corepressor complex, but has also been shown to physically interact with RB to repress E2F target genes. More recently, it was suggested that the tandem Tudor domain of JHDM3A_JMJD2A potentially contains a chromatin targeting module that directly binds methylated H3K4, H3K9 and H4K20. (1)